Arnaud Desplechin knows about families and has assembled a great cast for this sprawling story of the Vuillard clan in Roubaix, northern France. The brood assemble for Christmas and proceed to tear each other apart — sometimes gently, often violently.

Catherine Deneuve and Jean-Paul Roussillon play Junon and Abel, the unfortunate hosts. She has degenerative cancer which can only be cured by a bone marrow transplant — if an appropriate donor from the family can be persuaded to undertake one. There’s their elder daughter (Anne Consigny), who quarrels with her black-sheep brother (Mathieu Amalric). Then there’s the younger son (Melvil Poupaud), whose wife (Chiara Mastroianni) sleeps with her husband’s cousin (Laurent Capelluto) in a fit of pique. And there’s a lot more besides.

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Sometimes it is difficult to make out who means what to whom as the extended family celebrate Yuletide with some good cheer added to the quarrelsome mix. This could be called a tragic comedy, and Desplechin orchestrates it all with the skill of a minor master armed with an excellent script.

The result is consistently watchable, with Deneuve a grave but brave presence at its centre and her elderly husband a rock of comfort beside her. Half a million customers saw it in France and apparently found it truthful. So did I.